Novel Biological Methods for Decontamination of Flowback Water
Saeed Keshani, Sean-­‐Erik O'Donnell, Melika Riley, Christopher Sales Department of Civil, Architectural and Environmental Engineering INSTITUTE FOR ENERGY AND THE ENVIRONMENT (IEXE) Results Introduc)on Objec)ve •
Haloferax volcanii, Rhodococcus sp. RR1, Janibacter Hydraulic fracturing is used to extract natural gas •
poten@al ability of bacterial species in removal of sp., Marinobacterium georgiense, and and oil from shale layers deep underground. This selected contaminants from the simulated flowback Pseudonocardia d
ioxanivorans C
B1190 w
ere a
ble t
o process generates large volumes of high-­‐salinity water. grow at salinity levels over 10% (Figure 2). flowback water, o?en contaminated with organic •
None of these bacteria are able to grow on or in the cons@tuents such as phenols and PAHs; these MICROBIAL SELECTION presence of pentachlorophenol (PCP), when 1mM organic cons@tuents are generally derived from the pure PCP was added as the sole source of carbon. proppants and other chemicals used to change the •
Co-­‐metabolic studies performed with PCP and proper@es of the fracturing fluid. Due to these CULTURE fructose demonstrated that Rhodococcus sp. RR1 characteris@cs, remedia@on of flowback water by and Haloferax volcanii were capable of removing conven@onal wastewater treatments such as 20% of the spiked PCP over a period of 7 days underground injec@on and discharge and dilu@on TEST GROWTH ON (Figure 5). to publicly owned treatment plants are o?en CONTAMINANTS (METABOLISM) Figure 1: Bacterial growth in selected media ineffec@ve. In this study, biological remedia@on is to induce PCP degrada)on enzymes evaluated as an alterna@ve strategy for removal of CB1190 growth Haloferax Growth in Salt 0.1 TEST G
ROWTH O
N I
NDUCING organic cons@tuents. Because this is believed that 0.08 SUBSTRATES 0.08 some species of bacteria are able to degrade (COMETABOLISM) 0.07 %0NaCl 0.06 %2NaCl 0.06 aroma@c hydrocarbons in hypersaline environment %12NaCl %5NaCl 0.04 0.05 %15NaCl 1,2,3. %7NaCl 0.02 0.04 %17NaCl %10NaCl %20NaCl CULTURE IN FLOWBACK WATER 0.03 0 %12NaCl 0 1 2 3 4 %25NaCl 0.02 %15NaCl -­‐0.02 In bioremedia@on, contaminant degrada@on can %30NaCl %20NaCl 0.01 -­‐0.04 occur metabolically (direct incorpora@on into 0 -­‐0.06 0 1 2 3 4 TEST DEGRADATION OF -­‐0.01 biomass) or cometabolically (indirect removal CONTAMINANTS IN FLOWBACK Figure 4: Pseudonocardia dioxanivorans CB1190 growth in salt (METABOLISM & during growth on other primary substrate). In this Figure 3
: H
aloferax v
olcanii g
rowth i
n s
alt COMETABOLISM) study, we use so-­‐called “inducer” substrates to RR1 Growth in Salt encourage the produc@on of monooxygenase (MO) Methods and Materials 1.6 enzymes by the microbes. MO enzymes are •
Workflow of this project are shown in the flowchart. Green boxes 1.4 %0NaCl 1.2 instrumental in the degrada@on of the organic represent the completed works and orange boxes represent the future %2NaCl 1 %5NaCl cons@tuents targeted by our study. steps. 0.8 %7NaCl %10NaCl •
The bacterial cells are grown in defined media (W) in 30⁰C with 0.6 %12NaCl PCP DERGRADATION RESULTS 0.4 different c
oncentra@on o
f s
alts 0
-­‐
30%; T
he g
rowth e
xperiment w
as %15NaCl 3,500,000 0.2 %20NaCl measured by light spectrometer wave length of 600 µm. 0 3,000,000 0 1 2 3 4 5 6 7 8 •
The bacterial culture was growth using hexane, toluene and benzene to -­‐0.2 2,500,000 Figure 2: Rhodococcus sp. RR1 growth in salt induce degrada@on enzymes. Because of the inhibitory effect of these RR1_fructose RR1_hexane chemicals o
n b
acterial g
rowth i
n h
igher c
oncentra@on t
hey d
idn’t 2,000,000 RR1_benzene References RR1_toluene spiked t
o t
he m
edia d
irectly; i
nstead, t
hey p
laced i
n a
s
mall v
ials a
nd 1.
Margesin, R.; Schinner, F., Biodegrada@on and 1,500,000 haloferax_hexane bioremedia@on of hydrocarbons in extreme environments. hanged o
ver t
he m
edia s
o t
he v
apor p
hase o
f t
hese h
ydrocarbons haloferax_benzene Applied Microbiology and Biotechnology 2001, 56, (5-­‐6), 1,000,000 haloferax_toluene served as source of carbon (Figure 1); then rich bacterial culture 650-­‐663. 2.
Semprini, L., Strategies for the aerobic co-­‐metabolism of 500,000 transferred to the media contain PCP. chlorinated solvents. Current Opinion in Biotechnology •
Samples were regularly withdrawn from bacterial cultures and analyzed 1997, 8, (3), 296-­‐308. 0 0 1 2 3 4 5 6 7 3.
Xuliang, Z.; Han, Z.; Bai, Z.; Zhuang, G.; Shi, H., Progress in for PCP content by high-­‐performance liquid chromatography (HPLC) in decontamina@on by halophilic microorganisms in saline Figure 5: PCP degrada)on by cometabolism wastewater and soil. Environmental Pollu@on 2010, 158 order to determine an overall rate of degrada@on. (5),1119-­‐1126.